Prevalence and correlations of anal incontinence and constipation in Taiwanese women

Anal incontinence and constipation are not only physically and psychologically disabling symptoms but also a significant social and public health problem. The epidemiology of anal incontinence and constipation from community-bases remains largely unknown, especially in Asian women. This study is a continuation of a previous survey taken on the epidemiology of urinary incontinence and overactive bladder in Taiwanese women by using a second questionnaire (correlation coefficient for symptoms, r=0.87; P<0.05). We evaluated the prevalence and potential risk factors associated with anal incontinence and constipation in the general population. Of the 1,584 (2.92%) women sampled, 1,253 (79.1%) were successfully interviewed at home. The prevalence of fecal incontinence and flatus incontinence was 35 (2.8%) and 107 (8.6%), respectively. There were 306 (24.5%) participants who reported constipation. However, according to the current medical criteria for constipation, the prevalence of constipation was only 2.7%. The prevalence of anal incontinence did not increase after the age of 65 years (9.7%, including 3.5% of elderly women with fecal incontinence and 6.2% of elderly women with flatus incontinence). The prevalence of constipation significantly increased in the women aged 65 years and over (self-reported prevalence: 32.4%, fitted in medical criteria for constipation: 8.3%). Our results demonstrated that constipation shares some of the same risk factors, namely, symptoms of uterovaginal prolapse, prior gynecologic surgery, and overactive bladder that predispose women to the occurrence of anal incontinence. The questionnaire needs a higher discriminatory capacity, and a longitudinal study should be conducted to clarify this conflict further.